Spectrophotometric and Liquid Chromatographic Methods for Quantification of Antibacterial Fluorescent Dye (Phloxine B) in Dental Disclosing Tablets and Toothpaste Samples.

Double beam UV-Vis spectrophotometry and high-performance liquid chromatography (HPLC) techniques have been used to determine the antibacterial fluorescent phloxine B dye in dental preparations. In the visible wavelength range of 400 to 800 nm, the spectrophotometric signal was obtained at λmax = 539 nm. The HPLC process used C-18 (5 μm) with a UV detector at 254 nm, 1.5 mL/min flow rate, 0.635 min retention time, and water, acetonitrile, and 2-propanol as the mobile phase. Several parameters have been used to analyze the performance of the HPLC and double-beam UV-Vis spectrophotometry apparatuses, including stability, detection and quantification limits, calibration curves, and repeatability. The study focused on the repeatability of spectrophotometric and HPLC procedures for 8 × 10–6 and 5 × 10–6 mol/L of phloxine B. The results showed that the standard deviation (STD) for ten spectrophotometric measurements and eight HPLC measurements, respectively, was ± 0.0004 and ± 2.487 with relative standard deviation (RSD%) of 0.048 and 1.05%. Throughout 90 min of the analysis period, the spectrophotometric and HPLC signals for 8 × 10–6 and 5 × 10–6 mol/L of phloxine B were shown to be exceptionally stable. The ranges of the calibration curves were 1 × 10-6–2 × 10–5 mol/L for the spectrophotometry and 1 × 10–5–1 × 10–4 mol/L for HPLC. Within the concentration ranges under consideration, they were assigned linear relations with correlation coefficients (r2) of 0.9995 for spectrophotometric and 0.99 for HPLC measurements. The detection limits for phloxine B were found to be 1.24 × 10–8 mol/L (0.0103 ppm) and 8.25 × 10–7 mol/L (0.068 ppm), respectively, using double-beam UV-visible spectrophotometry and HPLC methods. These techniques use recovery rates ranging from 95 to 111% to determine the phloxine B dye that has been spiked in disclosing tablets and toothpaste samples. [ABSTRACT FROM AUTHOR]